Struct LevelFilter

pub struct LevelFilter(/* private fields */);

A filter comparable to a verbosity [Level].

If a [Level] is considered less than or equal to a LevelFilter, it should be considered enabled; if greater than the LevelFilter, that level is disabled. See LevelFilter::current for more details.

Note that this is essentially identical to the Level type, but with the addition of an OFF level that completely disables all trace instrumentation.

See the documentation for the [Level] type to see how Levels and LevelFilters interact.

Implementations

impl LevelFilter

pub const OFF: LevelFilter = _

The “off” level.

Designates that trace instrumentation should be completely disabled.

pub const ERROR: LevelFilter = _

The “error” level.

Designates very serious errors.

pub const WARN: LevelFilter = _

The “warn” level.

Designates hazardous situations.

pub const INFO: LevelFilter = _

The “info” level.

Designates useful information.

pub const DEBUG: LevelFilter = _

The “debug” level.

Designates lower priority information.

pub const TRACE: LevelFilter = _

The “trace” level.

Designates very low priority, often extremely verbose, information.

pub const fn from_level(level: Level) -> LevelFilter

Returns a LevelFilter that enables spans and events with verbosity up to and including level.

pub const fn into_level(self) -> Option<Level>

Returns the most verbose [Level] that this filter accepts, or None if it is OFF.

pub fn current() -> LevelFilter

Returns a LevelFilter that matches the most verbose Level that any currently active Subscriber will enable.

User code should treat this as a hint. If a given span or event has a level higher than the returned LevelFilter, it will not be enabled. However, if the level is less than or equal to this value, the span or event is not guaranteed to be enabled; the subscriber will still filter each callsite individually.

Therefore, comparing a given span or event’s level to the returned LevelFilter can be used for determining if something is disabled, but should not be used for determining if something is enabled.

Trait Implementations

impl AsLog for LevelFilter

type Log = LevelFilter

The log type that this type can be converted into.

fn as_log(&self) -> <LevelFilter as AsLog>::Log

Returns the log equivalent of self.

impl Clone for LevelFilter

fn clone(&self) -> LevelFilter

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LevelFilter

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl Display for LevelFilter

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<S> Filter<S> for LevelFilter

fn enabled(&self, meta: &Metadata<'_>, _: &Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given Metadata in the current Context, similarly to Subscriber::enabled.

fn callsite_enabled(&self, meta: &'static Metadata<'static>) -> Interest

Returns an Interest indicating whether this layer will always, sometimes, or never be interested in the given Metadata.

fn max_level_hint(&self) -> Option<LevelFilter>

Returns an optional hint of the highest verbosity level that this Filter will enable.

fn event_enabled(&self, event: &Event<'_>, cx: &Context<'_, S>) -> bool

Called before the filtered [Layer]'s [on_event], to determine if on_event` should be called.

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a new span was constructed with the given Attributes and Id.

fn on_record(&self, id: &Id, values: &Record<'_>, ctx: Context<'_, S>)

Notifies this filter that a span with the given Id recorded the given values.

fn on_enter(&self, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID was entered.

fn on_exit(&self, id: &Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID was exited.

fn on_close(&self, id: Id, ctx: Context<'_, S>)

Notifies this filter that a span with the given ID has been closed.

impl From<Level> for LevelFilter

fn from(level: Level) -> LevelFilter

Converts to this type from the input type.

impl From<Option<Level>> for LevelFilter

fn from(level: Option<Level>) -> LevelFilter

Converts to this type from the input type.

impl FromStr for LevelFilter

type Err = ParseLevelFilterError

The associated error which can be returned from parsing.

fn from_str(from: &str) -> Result<LevelFilter, <LevelFilter as FromStr>::Err>

Parses a string s to return a value of this type.

impl Hash for LevelFilter

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<S: Subscriber> Layer<S> for LevelFilter

fn register_callsite(&self, metadata: &'static Metadata<'static>) -> Interest

Registers a new callsite with this layer, returning whether or not the layer is interested in being notified about the callsite, similarly to Subscriber::register_callsite.

fn enabled(&self, metadata: &Metadata<'_>, _: Context<'_, S>) -> bool

Returns true if this layer is interested in a span or event with the given metadata in the current Context, similarly to Subscriber::enabled.

fn on_register_dispatch(&self, subscriber: &Dispatch)

Performs late initialization when installing this layer as a Subscriber.

fn on_layer(&mut self, subscriber: &mut S)

Performs late initialization when attaching a Layer to a [Subscriber].

fn on_new_span(&self, attrs: &Attributes<'_>, id: &Id, ctx: Context<'_, S>)

Notifies this layer that a new span was constructed with the given Attributes and Id.

fn on_record(&self, _span: &Id, _values: &Record<'_>, _ctx: Context<'_, S>)

Notifies this layer that a span with the given Id recorded the given values.

fn on_follows_from(&self, _span: &Id, _follows: &Id, _ctx: Context<'_, S>)

Notifies this layer that a span with the ID span recorded that it follows from the span with the ID follows.

fn event_enabled(&self, _event: &Event<'_>, _ctx: Context<'_, S>) -> bool

Called before on_event, to determine if on_event should be called.

fn on_event(&self, _event: &Event<'_>, _ctx: Context<'_, S>)

Notifies this layer that an event has occurred.

fn on_enter(&self, _id: &Id, _ctx: Context<'_, S>)

Notifies this layer that a span with the given ID was entered.

fn on_exit(&self, _id: &Id, _ctx: Context<'_, S>)

Notifies this layer that the span with the given ID was exited.

fn on_close(&self, _id: Id, _ctx: Context<'_, S>)

Notifies this layer that the span with the given ID has been closed.

fn on_id_change(&self, _old: &Id, _new: &Id, _ctx: Context<'_, S>)

Notifies this layer that a span ID has been cloned, and that the subscriber returned a different ID.

fn and_then<L>(self, layer: L) -> Layered<L, Self, S>

where L: Layer<S>, Self: Sized,

Composes this layer around the given Layer, returning a Layered struct implementing Layer.

fn with_subscriber(self, inner: S) -> Layered<Self, S>

where Self: Sized,

Composes this Layer with the given Subscriber, returning a Layered struct that implements Subscriber.

fn with_filter<F>(self, filter: F) -> Filtered<Self, F, S>

where Self: Sized, F: Filter<S>,

Combines self with a Filter, returning a Filtered layer.

fn boxed(self) -> Box<dyn Layer<S> + Send + Sync + 'static>

where Self: Sized + Layer<S> + Send + Sync + 'static, S: Subscriber,

Erases the type of this Layer, returning a Boxed dyn Layer trait object.

impl Ord for LevelFilter

fn cmp(&self, other: &LevelFilter) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq<Level> for LevelFilter

fn eq(&self, other: &Level) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialEq for LevelFilter

fn eq(&self, other: &LevelFilter) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd<Level> for LevelFilter

fn partial_cmp(&self, other: &Level) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Level) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Level) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Level) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Level) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl PartialOrd for LevelFilter

fn partial_cmp(&self, other: &LevelFilter) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &LevelFilter) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &LevelFilter) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &LevelFilter) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &LevelFilter) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Copy for LevelFilter

impl Eq for LevelFilter

impl StructuralPartialEq for LevelFilter